Buddleja plant named ‘Blue Chip’

ABSTRACT

Buddleja  ‘Blue Chip’ is a new and distinct variety of butterfly bush that has the following unique combination of desirable features that are outstanding in a new variety.
         1. Moderate vigor resulting in compact growth habit.   2. Ease of asexual propagation using softwood or semi-hardwood cuttings.   3. Spreading growth habit with multi-branched stems.   4. Male sterility, and low female fertility and reduced seed set, resulting in less opportunity for seedlings to originate in the landscape setting.   5. Blue flower color.

Latin name of the genus and species: Genus: Buddleja. Species: complexhybrid including davidii, lindleyana, and globosa.

Variety denomination: The inventive cultivar of Buddleja disclosedherein has been given the variety denomination ‘Blue Chip’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct variety of Buddlejadavidii (butterfly bush) grown as an ornamental shrub for home andcommercial landscapes. Butterfly bush is typically grown for itsattractive, fragrant flowers that are borne throughout the growingseason.

The new and distinct variety of butterfly bush resulted from a formalbreeding program established by the inventors in Raleigh, N.C. UnitedStates. One of the objectives of the breeding program was to develop acompact, spreading Buddleja with blue flower color. ‘Blue Chip’originated as a third generation descendant from a hand pollinated crossof ‘Honeycomb’×(‘Nanho Purple’×Buddleja lindleyana) made in 2001.‘Honeycomb’ (unpatented) was released in 1997, and is described as ahybrid of Buddleja davidii and Buddleja globosa. ‘Nanho Purple’(unpatented) is a semi-compact selection of Buddleja davidii var.nanhoensis. Buddleja lindleyana is a species native to China. All threeparents are available in commerce.

The seeds resulting from the 2001 controlled hybridization process wereharvested in fall of 2001 and germinated in a greenhouse in Raleigh,N.C. in the winter of 2002. The resulting 32 seedlings were planted infield trials in spring of 2002. These plants flowered in summer 2002,and seed was collected off of all plants and bulked. This bulk seed wasgerminated in a greenhouse in Raleigh, N.C. in the winter of 2003. Theresulting 69 seedlings were planted in the field in spring of 2003.These plants flowered in summer 2003, and one plant, designatedNC2003-7, was selected for its compact growth habit and attractive blueflowers. Open pollinated seed was collected off of NC2003-7. This bulkseed was germinated in a greenhouse in Raleigh, N.C. in the winter of2004. The resulting 11 seedlings were planted in the field in spring of2004. These plants flowered in summer 2004, and one plant, designatedNC2004-9, was selected for its multi-branched, compact growth habit andattractive blue flowers. This original plant demonstratedcharacteristics identical to those subsequently expressed on otherplants when propagated from stem cuttings. This single plant is thesubject of the present invention ‘Blue Chip’.

The distinguishing traits of ‘Blue Chip’ are compact growth habit,multi-branched stems, gray-green leaf color, and flowers that are bluein color. The cultural requirements for ‘Blue Chip’ are well-drainedsoil, full sun, and moderate moisture. ‘Blue Chip’ exhibits no seriouspest or disease problems known to the inventors, except for occasionalspider mite infestation during periods of hot, dry weather.

The closest comparison known to the inventors is the cultivar ‘Ellen'sBlue’ (unpatented). Plants and flowers of this new variety differ from‘Ellen's Blue’. In direct comparisons of the 2 cultivars in theinventor's experimental trials, plants of ‘Blue Chip’ are consistentlymore compact, more highly branched, more dense, and produce less viableseed than ‘Ellen's Blue’. ‘Blue Chip’ is distinctly different from allthree of its original parents.

The first asexual propagation of ‘Blue Chip’ was conducted by theinventors in fall 2004 in Raleigh, N.C., and ‘Blue Chip’ hassubsequently been propagated in the same location in years 2005 and2006. In all cases, the original plant selection was propagatedasexually by softwood to semi-hardwood stem cuttings. Such cuttings rootreadily under mist in about 14 to 21 days, and resume normal growth.Five plants derived from stem cuttings of the variety were establishedin test plots at Sandhills Research Station and the Horticultural FieldLaboratory in 2005, and ten additional plants derived from stem cuttingsof the variety were established at the Sandhills Research Station in2007. During all asexual propagation, the characteristics of theoriginal plant have been maintained. Plants derived from stem cuttingsexhibit characteristics identical to those of the original plant, and noaberrant phenotypes have appeared.

Test plantings and performance evaluation over three years at theSandhills Research Station and Horticulture Field Laboratory demonstratethis variety to be relatively consistent in its characteristics evenunder the different growing conditions associated with yearly climaticvariation.

Plants of the new variety are only moderately vigorous afterestablishment in the field, being less vigorous and more compact thanmost cultivars of butterfly bush. Young plants have averaged about 0.4meters of growth per year. Plants are spreading in growth habit.Flowering occurs in the first year of growth on newly formed wood. Theinflorescence is a simple panicle, and shows a blue flower color.Flowering usually begins in late May to early June in Jackson Springs,N.C., and continues throughout the growing season until the first freezeevent in October or November. An individual inflorescence flowers forabout 7-10 days, depending on temperature, but new flowers are madeduring the entire growing season. Fertility of flowers is low, and thenew cultivar sets very few seed, an asset-in landscape settings.

‘Blue Chip’ is distinguished from other related known cultivars based onthe unique combination of traits including compact growth habit,multiple-branched stems, and blue flower color.

The new variety has been named the BLUE CHIP cultivar. No public sale of‘Blue Chip’ has yet taken place at the time of application.

SUMMARY OF THE INVENTION

‘Blue Chip’ is a new and distinct variety of butterfly bush that has thefollowing unique combination of desirable features outstanding in a newvariety. In combination these traits set ‘Blue Chip’ apart from allother existing varieties of butterfly bush known to the inventors.

-   -   1. ‘BLUE CHIP’ has moderate vigor resulting in compact growth        habit.    -   2. ‘BLUE CHIP’ is asexually propagated using softwood or        semi-hardwood cuttings.    -   3. ‘BLUE CHIP’ demonstrates spreading growth habit and        multi-branched stems.    -   4. ‘BLUE CHIP’ exhibits low female fertility and reduced seed        set, resulting in less opportunity for seedlings to originate in        the landscape setting.    -   5. ‘BLUE CHIP’ has blue flower color.

BRIEF DESCRIPTION OF THE DRAWINGS

The photographs in the drawings were made using digital photographytechniques, and show the colors as true as reasonably possible bydigital photography. Colors in the photographs may differ slightly fromthe color values cited in the detailed botanical description, whichaccurately describe the colors of the new Buddleja variety ‘BLUE CHIP’.All photographs were taken from two-year-old plants growing at theHorticulture Field Laboratory, Raleigh, N.C.

FIG. 1 shows a typical plant of ‘BLUE CHIP’, showing the compact growth,spreading habit, multi-branched stems, and blue flowers.

FIG. 2 shows a close-up view of the inflorescence of ‘BLUE CHIP’,showing the blue color of the individual flowers in the inflorescence.

FIG. 3 shows the typical coloration and form of leaves of ‘BLUE CHIP’.

This figure shows the lower and upper leaf surface.

DETAILED BOTANICAL DESCRIPTION OF THE VARIETY

The following is a detailed description of the botanical and ornamentalcharacteristics of the subject butterfly bush ‘BLUE CHIP’. Color dataare based on The Royal Horticultural Society Colour Chart, The RoyalHorticultural Society, London, 2001 edition. Where dimensions, sizes,colors and other characteristics are given, it is to be understood thatsuch characteristics are approximations of averages set forth asaccurately as practicable.

The descriptions reported herein are from two-year-old specimens grownout-of-doors in Raleigh, N.C.

-   Genus: Buddleja.-   Species: Complex hybrid, including davidii, globosa, and lindleyana.-   Denomination: ‘BLUE CHIP’.-   Commercial Classification: Shrub, deciduous.-   Common name: Butterfly bush.-   Type: Ornamental.-   Uses: Patio container plant, herbaceous perennial border, or shrub    border for residential and commercial landscapes.-   Cultural requirements: Full sun exposure, well-drained soil, and    moderate moisture.-   Parentage: ‘BLUE CHIP’ is a third-generation hybrid that resulted    from the original cross pollination of the following Buddleja    parents: Seed parent=‘Honeycomb’ Pollen parent=hybrid of ‘Nanho    Purple’×Buddleja lindleyana.-   Plant description:    -   -   Blooming period.—Spring, summer, and early fall until frost.        -   Blooming habit.—Spreading to semi-upright with narrow            flowers.        -   Vigor.—Low vigor.        -   Plant habit.—Compact, spreading habit.        -   Height and spread.—0.46 meters (height) and 1.4 meters            (width).        -   Hardiness.—To date, hardy to minus 8 degrees Centigrade. Not            tested below this temperature. Anticipated adapted from USDA            hardiness zones 5-9.        -   Propagation.—Softwood to semi-hardwood cuttings under            intermittent mist. Roots typically form in 2-3 weeks.        -   Root system.—Fibrous.        -   Seasonal interest.—Blue flowers in spring, summer, and fall            on a compact shrub.        -   Disease and pest susceptibility and resistance.—No            particular susceptibility or resistance, except occasionally            susceptible to spider mites under very hot and dry            conditions.        -   Special growing requirements.—Severe yearly pruning in late            winter or early spring prior to bud break is recommended to            encourage more profuse flowering.-   Stems:    -   -   Shape.—Stem cross section is quadrangular.        -   Length.—Average 55 cm.        -   Color.—Yellow-green (RHS 144C) on recently formed shoots.        -   Diameter.—2-5 mm. near terminal portion of stem, and 8 mm.            near base of stem.        -   Stem surface.—Glaucous with slight pubescence.        -   Pubescence.—Sparse.        -   Internode length.—3.6 cm. between nodes-   Foliage:    -   -   Type.—Deciduous.        -   Leaf arrangement.—Opposite, decussate.        -   Leaf division.—Simple.        -   Leaf shape.—Elliptic.        -   Leaf base.—Attenuate.        -   Leaf apex.—Acuminate.        -   Leaf venation.—Pinnate.        -   Leaf surface (abaxial).—Glaucous.        -   Leaf margin.—Serrulate.        -   Leaf attachment.—Petiolate.        -   Petiole dimensions.—6.0 mm length. 1.0 mm. width.        -   Petiole shape.—Sulcate.        -   Petiole color.—Grayed-green (RHS 195A).        -   Leaf color.—Adaxial side=green (RHS 137A). Abaxial            side=grayed-green (RHS 191B).        -   Leaf length.—Average length (10 leaves)=9.5 cm.        -   Leaf width.—Average width (10 leaves)=3.6 cm.        -   Foliar fragrance.—None detectable.-   Flowers:    -   -   Inflorescence.—Terminal panicle.        -   Petals.—4 (occasionally 5) in number.        -   Fused or unfused.—Fused at base.        -   Petal margin.—Entire.        -   Petal apex.—Rounded lobes, serrulate.        -   Petal base.—Truncate.        -   Petal surfaces.—Glaucous.        -   Petal shape.—Rotund.        -   Petal dimensions.—11 mm. length. 4.0 mm. width.        -   Petal color.—Adaxial and abaxial surface=violet-blue (RHS            90C). Flower shape: Salverform.        -   Corolla tube color.—Inside surface=orange (RHS 25B).        -   Corolla tube surfaces (inner and outer surfaces).—Pubescent.        -   Corolla tube shape.—Tubular.        -   Color of peduncle.—Grayed-green (RHS 194A).        -   Peduncle surface.—Glaucous.        -   Peduncle length.—2.4 cm.        -   Peduncle shape.—Flattened oval in cross section.        -   Pedicel dimensions.—1.0 mm. in length and less than 1 mm. in            diameter.        -   Pedicel color.—Grayed-green (RHS 194A).        -   Pedicel shape.—Flattened oval in cross section.        -   Pedicel surface.—Glaucous.        -   Flowers persistent or self-cleaning.—Flowers are persistent.        -   Lastingness of the overall inflorescence.—3-4 weeks.        -   Lastingness of an individual flower.—3-5 days.        -   Dimensions of inflorescence.—7.8 cm. in length. 3.2 cm. in            diameter.        -   Dimensions of entire individual flower.—12 mm. length.            Diameter 6.0 mm. at apex tapering to 1 mm. at base.        -   Quantity of flowers.—198 flowers per individual            inflorescence (average of 5 panicles).        -   Bud color.—Violet-blue (RHS 90B to 90C).        -   Bud apex.—Rounded.        -   Bud surface.—Glabrous.        -   Bud shape.—Elongated, linear balloon.        -   Calyx shape.—Tubular.        -   Calyx dimensions.—2.0 mm. in width and 4.0 mm. in length.        -   Sepals.—Four in number.        -   Sepal shape.—Lanceolate.        -   Sepal apex.—Acute.        -   Sepal margin.—Entire.        -   Sepal surface.—Glabrous.        -   Sepal color.—Grayed-green (RHS 194B).        -   Flower fragrance.—Distinct sweet fragrance.-   Reproductive organs:    -   -   Stamens.—Four, fused to inside of petals.        -   Anther shape.—Oblong.        -   Anther dimensions.—1 mm. in length and 0.2 mm. wide.        -   Filament size.—3 mm. in length and less than 0.5 mm. in            width.        -   Filament color.—Yellow-white (RHS 158B).        -   Pollen amount.—None produced.        -   Pollen color.—Not applicable. None produced.        -   Pistil.—One in number.        -   Pistil dimensions.—3 mm. in length, and less than 1 mm. in            diameter.        -   Stigma color.—Yellow-green (RHS 144A).        -   Ovary.—Present, but often malformed.        -   Ovary position.—Superior.        -   Ovary shape.—Oval.        -   Fertility.—Self-unfruitful. Requires cross pollination. Male            sterile, and low female fertility.-   Fruit:    -   -   Type.—Swelled capsule.        -   Dimensions.—3.0 mm. in length (variable) and 1.6 mm. in            diameter (variable).        -   Color.—Yellow-green (RHS 144C) when immature.

1. A new and distinct variety of butterfly bush tree (Buddleja)substantially as illustrated and described, characterized by its compactgrowth habit, multi-branched stems, grayed-green leaf color, and blueflower color.